Once upon a time, a salt shaker fell in love with a girl

Late at night it would sneak into her bedroom along with popcorn, only to be discovered by the family later. Sometimes it would jump off the bedside table and roll under the bed to avoid detection, but they always found it.

Wait, that’s not right. I’m pretty sure it was the other way around, and it was the girl who was in love with salt . . . they used to call her The Salt Bandit or something. Yeah, that’s definitely it. I should know, because that person is me.

My salt cravings are no mystery – they nourish the adrenals, which tend to be weak in my family. As part of the endocrine system, they’re inextricably linked to another organ we all need to be talking about – the thyroid.

Seriously, we do. According to The American Thyroid Association, one in eight women will develop a thyroid disorder in her lifetime, but about 60% of those affected will never know. (source)

If you’re struggling with low energy levels, difficulty focusing, moodiness or an inability to maintain a healthy weight, you might be one of those women. The numbers for men are better, but not by much. In this post, I’ll share a simple at-home test that many practitioners recommend to determine whether there might be a problem. (Note: This post is not intended to diagnose, treat, or cure any disease. I am simply sharing an at-home observation technique that many practitioners recommend to their patients as part of an overal diagnostic process.)

The Thyroid Sessions ~ Free Next Week

Just as a heads up: Starting May 4th, you can get access to information on thyroid health that you’re not likely to find in a doctor’s office. The Thyroid Sessions is a no-cost online event featuring respected thyroid experts on how to properly diagnose, treat, and reverse thyroid problems naturally.

How Basal Body Temperature Indicates Thyroid Function

The thyroid is often called the “thermostat” of the body, because it produces the hormone we need to keep warm. It does this by converting a hormone made by the pituitary gland, TSH, into T4 and T3. Unfortunately, when the thyroid is struggling it is unable to keep the body at the right temperature setting. Certain enzymes don’t function as well under colder/hotter conditions, which can set a number of disease processes in motion.

According to the Mayo Clinic, low thyroid can lead to heart disease, depression, infertility, birth defects, myxedema, peripheral neuropathy, and goiter. (source)

Why your thyroid might be off even if you your tests come back normal:

Do you have all the symptoms of hypothyroidism, and yet your tests come back normal? According to some experts, the TSH test used to determine thyroid function is not always reliable. Here’s why: The hormone T4 is inactive in the body, so the body converts it to active T3.

“Usually, medicine will diagnose thyroid disease by testing for TSH levels, or the amount of T3 and T4 hormone in the blood. Bring back to mind, however, that T3 is the primary hormone which helps regulate body temperature – not T4!

Hence, if – despite adequate secretion of T4 by the thyroid gland – we’re not getting sufficient conversion of T4 to T3, or T3 is unable to activate cellular receptor sites, then the basal body temperature, or BBT will be found to be low – as will thyroid function.

In other words, using your body basal temperature provides us with a more realistic understanding of how efficiently your thyroid gland is actually functioning – compared to thyroid testing, done on a blood sample, which only measures how much hormone is present in that specific amount of blood – not how active it is.

Consequently, measuring your basal body temperature makes it possible to achieve a far more authentic way of testing for true thyroid function. It’s based on the simple, yet scientific premise that in a sense, your thyroid is much like the thermostat in your air-conditioned home.”

Easy At-Home Test For Evaluating Thyroid Function

This test should not be used as a sole diagnostic tool. Rather, it is something you can do at home to identify a possible problem to talk over with your trusted healthcare provider.

What you’ll need to check your thyroid at home:

A good basal body thermometer (not a regular digital one) or an old-fashioned glass thermometer with mercury. These two types of thermometers are calibrated differently and can report slightly different temperatures. The test was developed with a glass thermometer and is therefore the preferred tool for accuracy, but I choose not to keep one in the house. Instead, I use a high-quality digital thermometer that is very sensitive, and I compare my results with overall symptoms. (See thyroid function quiz below)

1. Place thermometer by your bed before you go to sleep. You’ll need to be able to reach it without getting out of bed or exerting much energy. If you’re using a glass thermometer, shake it thoroughly to reset it. The mercury will need to fall beneath 95F.

2. Over a period of three days, take your temperature immediately after waking up. It should be done around the same time each day before getting out of bed. To do this, place your thermometer under your armpit for 10 minutes while you lie down and rest your eyes without moving around a lot. If you’re using a digital thermometer, press the button at the end of 10 minutes to check your temperature.

3. Write down your temperature, the time, and date on a piece of paper.

4. Repeat this process for 3 consecutive days total.

Special note for menstruating women;

Your temperature naturally fluctuates through out your cycle. In order to get accurate reading for this assessment, start taking your temperature the day after you start your period.

What should I be looking for?

According to many experts, “A healthy resting temperature ranges between 97.8 to 98.2 degrees Fahrenheit or 36.6 to 36.8 degrees Celsius.” (source) In other words, “If your temperature is consistently lower than the range indicated above for at least three days, this may be an indication of [possible] hypothyroidism. Conversely, temperatures consistently higher than this may indicate hyperthyroidism but can also suggest a possible infection.” (source)

On the other hand, some doctors consider any temperature below 98 degrees to be suggestive of possible hypothyroidism. (source) Remember, this test is considered to be helpful in identifying possible thyroid dysfunction, but it should not be used as a sole piece of diagnostic criteria.

Factors that can affect your waking temperature

As Michelle points out in the comments, certain conditions unrelated to thyroid function can cause you to have an elevated waking temperature: Drinking alcohol the night before, extreme stress and hormonal birth control could cause elevated temperatures. On the flipside, recently discontinuing birth control could cause lower temperatures.

Do you have symptoms of hypothyroidism? Take the quiz

Some doctors, such as Dr. Brownstein, rely on patient history, clinical symptoms, and blood work to determine how well an individuals thyroid is functioning. Before the TSH test was available, doctors went by a clinical diagnosis alone.

Don’t Forget To Register For The Thyroid Sessions

It’s going to be an eye-opening event. If you’re interested in learning how to properly diagnose, treat, and reverse thyroid problems naturally for FREE, you’ll definitely want to check it out. As soon as youregisteryou’ll get immediate access to a 39 minute video interview with Dr. Tom O’Bryan on the gluten-thyroid connection, then when the sessions open you’ll get an invitation via email.

Here are a few things I’m looking forward to learning:

How to deal with the fatigue, brain fog, and endless juggling act of motherhood

The gluten-containing medication that can make your thyroid worse!

What your eyebrows, lashes, and ﬁngernails can tell you about your thyroid

Why you might have thyroid problems even when your tests come back normal

How to lose weight when your thyroid is off…or has been removed altogether

Hi, I'm Mommypotamus. My mission is to help you put delicious, healthy meals on the table, find effective natural remedies for common complaints, make your own fuss-free personal care and home products, and save time and money in the process.

My thyroid has been swollen for about 2 years. Not majorly, just enough that it’s been noticed by three different doctors during routine exams, yet the blood tests always come back fine, I’m going to have to try this.

Also, the little half moons on your finger nails are indicators of good thyroid function. If you’ve got them, you’re on the right track. I find them constantly reassuring after my years on thyroid meds.

I liked the quiz, but it only tests for hypothyroidism. My total added up to 80, so I have little chance of hypothyroidism but my concern was for hyperthyroidism which is often much more difficult to detect and treat. Is there another quiz that you know of that is for hyperthyroidism?

Hello Heather. Thank you for the post. My normal basal temperature is between 36.2 and 36.5 so I guess I have hypothyroidism. And I have also salt cravings… Thanks for the link of The Thyroid Session, I have just signed in!

Hi Amy May,
I have been doing research on Iodine but have problems finding the dosages cause most give too low dosages. I know that Iodine in not only exellent for the thyroid but is needed in a lot more places in the body. Can you give me an indication of how much Iodine is needed ?

Let me get this straight… the trick is to warm up the thermometer for 10 minutes before turning it on? I tried doing the basal body temperature for fertility, but my numbers were all over the place. I took my temperature immediately upon waking and recorded it.

Becky, No need to let the thermometer warm up that much when you’re taking an oral temp. Heather said she just rubs hers in her hands for a few seconds when it’s cold to warm it up a bit. For temps taken under the armpit, though, it is beneficial to let it warm up. This method was developed using underarm temps (which are slightly different) so that is what we want to use.

Do you know if any stores carry this particular thermometer linked in your article? I got a regular digital thermometer from CVS or Walgreen’s and it promptly malfunctioned, so I don’t trust them and definitely want to get a higher quality one.

I believe you can also just use a regular thermometer but look for a higher waking temperature – I have read that anything below 98.6 (orally) indicates low metabolism/thyroid function. And I think the idea behind the 10 minute waiting time is that the thermometer itself can reduce your temp if you take it too soon after putting it under your arm You could warm it up in your hand first before putting it in your mouth and then just wait a minute or so to let it adjust to your actual temp.

A waking temp alone won’t accurately reflect what’s going on with your thyroid. If you have elevated stress hormones (which people with thyroid problems do) during the night they will prop up your morning temp.

Thanks for your comment, Cat! From what I understand, hypothyroid individuals tend to have low waking temps, but of course there are always exceptions. To some degree, taking temps over the course of three days could be helpful for identifying “one off” high waking temps. Of course, this is just one of many symptoms associated with hypothyroidism, so if I didn’t have it but had others I would still look into it. So glad you stopped by!

Heather –
I just want to say I enjoy your site and the vast majority of what you share, but I wanted to add for anyone who reads comments and makes it down this far that waking temperatures should not be used to diagnose a thyroid problem unless you are very familiar with your own patterns and your cycle (more below). Temperatures of 97.8 – 98.2 are rare in pre-ovulatory women — those are post-ovulatory temperatures. You advised that women take their temperature after their period starts, but that’s when temperatures drop in the cycle (they don’t go up again till after ovulation – I’m a FAM practicer and have taken my temperature EVERY morning for nearly a year now). Morning temps are affected by a lot of things, trust me I’ve been taking, and recording my temp for over 300 days in a row. What you are looking for is more than 3 days worth of data. Morning temps are a fairly complex interplay of different factors, and again, really should NOT be used to diagnose a thyroid problem (after only 3 days of recording), or really even indicate one unless, again, you are very familiar with your body temperature, your cycle, and your own patterns (i.e. how long you slept, how well, if you had alcohol the night before, etc., etc. affect your morning temps). A couple other things to illustrate the complexity: 1) if you’re on the pill, your temps will be elevated all the time, and 2) if you’ve recently come off the pill (or have other hormonal problems) you may have lower than normal temps NOT because of low thyroid but because of low progesterone (I had this problem and have since recovered from it and now have normal waking temps).

I say all this because this post leaves is a little too simplistic could be very misleading to the unexperienced basal body temperature taker.

Hi Michelle, thanks for your comment! I’ve been doing NFP for about 10 years now, and I definitely agree with you on the alcohol/sleep thing. Based on what I read, the temp taken right after the first day of one’s period is considered the baseline for this test. I agree that it is not common, but that may be more of an indication of how many women struggle with thyroid issues than anything else. Again, thanks for taking the time to share your thoughts. I’m going to update the post to reflect some of the nuances you mentioned.

Thanks Heather! Glad to hear you practice NFP (I suspected as much). It took me so long to make the leap to FAM/NFP and I’m sooo glad I did. I learned so much about my body. I had crazy low temps for awhile after quitting the pill and read in TCOYF (Taking Charge of Your Fertility) that low waking temps could indicate a thyroid problem, but those were in a different range than you indicate. Because my temps were low for awhile and because of posts on the web just like this one, I thought I might have a thyroid problem, but I didn’t. For me it was a mix not getting enough rest, hormonal disturbance from having just stopped the pill, and low calorie consumption. The funny thing is I realized after awhile that I had a weak luteal phase (from other symptoms) and when I treated that, my temps finally went up to normal (or what I and TCOYF consider normal range). But hormones are a complex interplay aren’t they? I used to get crazy salt cravings when on the pill and they’ve totally stopped since quitting and being off for nearly a year. If I can add anything to this discussion, it’s that the pill is terrible for you (coming from someone who was on it 13 years). It wrecks your body! So if you think you have an undiagnosed thyroid problem (not you Heather, the proverbial “you”) but you are taking birth control — quit that first, wait 6 months to a year and then decide. I thought I had so many health problems and felt like I was on a downward spiral of health at only 31 – turns out I had just one health problem — the pill.

I also chart my temp, but even after I ovulate the highest my temp is is around 97.6. But that is the highest highest. Not common even after ovulation. Most days it is around 95.5. I definitely agree that more than three days are necessary, because sometimes there is a random bizarre temperature that is not indicative of an overall pattern.

I was diagnosed with Hypothyroidism about 12 years ago and have been on Levothyroxine ever since however I have continued to have many syptoms even though for ten of the aforementioned years I have been on the same dose. I have my blood tested regularly but upon taking your quiz I scored a 526. Could this be due to the wrong TSH check or other health issues steming from my slow thyroid. I am sick and tired of shoveling money hand over fist to doctor who seem to be annoyed by my concerns and I generaly get the same cookie cutter answers. Should I request another more in depth blood test or is a high result such as my own even on meds par for the course??